XtManageChildren(3Xt)                BSD                 XtManageChildren(3Xt)



NAME
     XtManageChildren, XtManageChild, XtUnmanageChildren, XtUnmanageChild -
     manage and unmanage children

SYNTAX
     typedef Widget *WidgetList;

     void XtManageChildren(children, num_children)
           WidgetList children;
           Cardinal num_children;

     void XtManageChild(child)
           Widget child;

     void XtUnmanageChildren(children, num_children)
           WidgetList children;
           Cardinal num_children;

     void XtUnmanageChild(child)
           Widget child;

ARGUMENTS
     child     Specifies the child.

     children  Specifies a list of child widgets.

     num_children
               Specifies the number of children.

DESCRIPTION
     The XtManageChildren function performs the following:

     ⊕    Issues an error if the children do not all have the same parent or
          if the parent is not a subclass of compositeWidgetClass.

     ⊕    Returns immediately if the common parent is being destroyed;
          otherwise, for each unique child on the list, XtManageChildren
          ignores the child if it already is managed or is being destroyed and
          marks it if not.

     ⊕    If the parent is realized and after all children have been marked,
          it makes some of the newly managed children viewable:

          -    Calls the change_managed routine of the widgets' parent.

          -    Calls XtRealizeWidget on each previously unmanaged child that
               is unrealized.

          -    Maps each previously unmanaged child that has map_when_managed
               True.

     Managing children is independent of the ordering of children and
     independent of creating and deleting children.  The layout routine of the
     parent should consider children whose managed field is True and should
     ignore all other children.  Note that some composite widgets, especially
     fixed boxes, call XtManageChild from their insert_child procedure.

     If the parent widget is realized, its change_managed procedure is called
     to notify it that its set of managed children has changed.  The parent
     can reposition and resize any of its children.  It moves each child as
     needed by calling XtMoveWidget, which first updates the x and y fields

     and then calls XMoveWindow if the widget is realized.

     The XtManageChild function constructs a WidgetList of length one and
     calls XtManageChildren.

     The XtUnmanageChildren function performs the following:

     ⊕    Issues an error if the children do not all have the same parent or
          if the parent is not a subclass of compositeWidgetClass.

     ⊕    Returns immediately if the common parent is being destroyed;
          otherwise, for each unique child on the list, XtUnmanageChildren
          performs the following:

          -    Ignores the child if it already is unmanaged or is being
               destroyed and marks it if not.

          -    If the child is realized, it makes it nonvisible by unmapping
               it.

     ⊕    Calls the change_managed routine of the widgets' parent after all
          children have been marked if the parent is realized.

     XtUnmanageChildren does not destroy the children widgets.  Removing
     widgets from a parent's managed set is often a temporary banishment, and,
     some time later, you may manage the children again.

     The XtUnmanageChild function constructs a widget list of length one and
     calls XtUnmanageChildren.

SEE ALSO
     XtMapWidget(3Xt), XtRealizeWidget(3Xt)
     X Toolkit Intrinsics - C Language Interface
     Xlib - C Language X Interface